Fabrication of nano-volcanoes with embedded sub-micropores for seal resistance characterization and intracellular delivery

Abstract

High-aspect-ratio nanostructures can improve intracellular delivery through nanopores and enhance electrophysiological recordings by strengthening the physical coupling between cells and underlying micro/nanostructures. However, key properties of this cell–nanostructure interface, especially the seal resistance, remain poorly quantified. Here, we report a wafer-scale “nano-volcano” platform with integrated sub-micropores (800 nm diameter) and 100 nm-thick walls. The device supports cell culture, enables intracellular delivery, and allows direct electrical quantification of the cell/nanostructure seal resistance using low-amplitude DC measurements. These measurements are facilitated by the relatively large pore diameter, which reduces access resistance. The fabrication process is reliable and repeatable at the wafer level, consistently producing open pores and well-formed nano-volcano structures across the entire wafer. As a proof of concept, we cultured human embryonic kidney cells on the nano-volcano array, quantified seal resistance, and achieved intracellular delivery of propidium iodide. Overall, this platform provides a simple, scalable, and quantitative approach to intracellular delivery while enabling new biophysical insight into the cell–nanostructure interface, an insight that could guide improved seal formation in automated patch-clamp systems.